Biology chapter 3

Question 1

Amino Acid

Answer 1

An organic molecule containing a carboxyl

group and an amino group; serves as the monomer of proteins

Question 2

Biological Macromolecule

Answer 2

important cellular components and perform a wide array of functions necessary for the survival and growth of living organisms. The four major classes of biological macromolecules are carbohydrates, lipids, proteins, and nucleic acids.

Question 3

Carbohydrate

Answer 3

Biological molecules consisting of single-monomer sugars (monosaccharides),
two-monomer sugars (disaccharides), and polymers
(polysaccharides). Any of a large group of organic compounds occurring in foods and living tissues and including sugars, starch, and cellulose. They contain hydrogen and oxygen in the same ratio as water (2:1) and typically can be broken down to release energy in the animal body.

Question 4

Cellulose

Answer 4

A structural polysaccharide of plant cell walls
composed of glucose monomers. Cellulose molecules are linked by
hydrogen bonds into cable-like fibrils.

Question 5

Dehydration synthesis

Answer 5

the process of joining two molecules, or compounds, together following the removal of water.

Question 6

Denaturation

Answer 6

A process in which a protein
unravels, losing its specific structure and hence function; can be
caused by changes in pH or salt concentration or by high temperature.
Denaturation also refers to the separation of the two strands of
the DNA double helix, caused by similar factors.

Question 7

Deoxyribonucleic acid (DNA)

Answer 7

A double-
stranded helical nucleic acid molecule consisting of nucleotide
monomers with deoxyribose sugar and the nitrogenous bases adenine
(A), cytosine (C), guanine (G), and thymine (T). Capable of replicating,
DNA is an organism’s genetic material.

Question 8

Enzyme

Answer 8

A macromolecule, usually a protein, that serves as a
biological catalyst, changing the rate of a chemical reaction without
being consumed by the reaction.

Question 9

Glycogen

Answer 9

An extensively branched glucose storage polysaccharide
found in liver and muscle cells; the animal equivalent of
starch.

Question 10

Hormone

Answer 10

In animals, a regulatory chemical that travels in the blood
from its production site, usually an endocrine gland, to other sites,
where target cells respond to the regulatory signal. (2) In plants,
a chemical that is produced in one part of the plant and travels to
another part, where it acts on target cells to change their functioning

Question 11

Hydrolysis

Answer 11

A chemical reaction that breaks bonds
between two molecules by the addition of water; process by which
polymers are broken down and an essential part of digestion.

Question 12

Lipid

Answer 12

An organic compound consisting mainly of carbon and hydrogen
atoms linked by nonpolar covalent bonds, making the compound
mostly hydrophobic. Lipids include fats, phospholipids, and steroids
and are insoluble in water.

Question 13

Messenger RNA (mRNA)

Answer 13

The type of ribonucleic acid that encodes
genetic information from DNA and conveys it to ribosomes, where
the information is translated into amino acid sequences.

Question 14

Monomer

Answer 14

The subunit that serves as a building block

of a polymer.

Question 15

Monosaccharide

Answer 15

The simplest carbohydrate; a
simple sugar with a molecular formula that is generally some multiple
of CH2O. Monosaccharides are the monomers of disaccharides and
polysaccharides.

Question 16

Nucleic acid

Answer 16

A polymer consisting of many nucleotide monomers;
serves as a blueprint for proteins and, through the actions of proteins,
for all cellular structures and activities. The two types of nucleic acids
are DNA and RNA.

Question 17

Nucleotide

Answer 17

A building block of nucleic acids, consisting
of a five-carbon sugar covalently bonded to a nitrogenous base and
one or more phosphate groups.

Question 18

Peptide bond

Answer 18

The covalent bond between two amino acid units in a

polypeptide, formed by a dehydration reaction.

Question 19

Phospholipid

Answer 19

A lipid made up of glycerol joined to
two fatty acids and a phosphate group, giving the molecule two nonpolar
hydrophobic tails and a polar hydrophilic head. Phospholipids
form bilayers that function as biological membranes.

Question 20

Polymer

Answer 20

A large molecule consisting of many identical

or similar monomers linked together by covalent bonds.

Question 21

Polypeptide

Answer 21

A polymer (chain) of amino acids linked by peptide bonds.

Question 22

Polysaccharide

Answer 22

A carbohydrate polymer of many

monosaccharides (sugars) linked by dehydration reactions.

Question 23

Protein

Answer 23

A functional biological molecule consisting of one or more polypeptides
folded into a specific three-dimensional structure.

Question 24

Purine

Answer 24

A nitrogenous base that has a large double ring structure. Makes up nucleic acids (e.g. DNA and RNA) and certain alkaloids (e.g. caffeine and theophylline)

Question 25

Pyrimidine

Answer 25

A nitrogenous base that has a single-ring structure; one of the two general categories of nitrogenous bases found in DNA and RNA

Question 26

Ribonucleic acid (RNA)

Answer 26

A type of nucleic acid consisting
of nucleotide monomers with a ribose sugar and the nitrogenous
bases adenine (A), cytosine (C), guanine (G), and uracil (U); usually
single-stranded; functions in protein synthesis, gene regulation,
and as the genome of some viruses.

Question 27

Saturated fatty acid

Answer 27

A fatty acid in which all carbons in the hydrocarbon
tail are connected by single bonds and the maximum number of
hydrogen atoms are attached to the carbon skeleton. Saturated fats
and fatty acids solidify at room temperature.

Question 28

Starch

Answer 28

A storage polysaccharide in plants; a polymer of glucose.

Question 29

Transcription

Answer 29

The synthesis of RNA on a DNA template

Question 30

Translation

Answer 30

The synthesis of a polypeptide using the genetic information
encoded in an mRNA molecule. There is a change of “language”
from nucleotides to amino acids.

Question 31

Unsaturated fatty acid

Answer 31

A fatty acid that has one or more double
bonds between carbons in the hydrocarbon tail and thus lacks the
maximum number of hydrogen atoms. Unsaturated fats and fatty
acids do not solidify at room temperature.